1. Field of the Invention
The present invention relates to a flameproof resin composition having thermal stability.
2. Description of the Prior Art
Polyamides and polyesters have excellent characteristics of fabricatability, mechanical property, electric property and heat resistance and they have been used as shaped articles, fibers and films, which are widely used in the industries. From the viewpoint of safety against the firing of plastics, the requirement of flameproof has been seriously considered and the reduction of flammability of the resin has been required in some usages.
Heretofore, the method of imparting flameproofing characteristic to polyamides by adding melamine or cyanuric acid type compound have been proposed (Japanese Patent Publication Nos. 19941/1967; 1714/1972 and Japanese Unexamined Patent Publication Nos. 96640/1975 and 105744/1975).
The temperature for fabricating polyamides or polyesters are usually high such as 200.degree. to 300.degree. C. The flameproofing agents of melamine or cyanuric acid type compound are easily decomposed at the fabrication to be disadvantageous in the practical operation.
The disadvantages are caused by the following reasons.
(1) Melamine initiates to sublimate at higher than 220.degree. C. whereby bubbles are incorporated in the product and the mechanical characteristics are deteriorated. PA1 (2). Cyanuric acid is easily decomposed by the thermal decomposition whereby the fabrication at higher than 250.degree. C. is difficult. PA1 (3) The miscibility of melamine or cyanuric acid to resins is not good whereby it is necessary to pulverize the resins to be less than 50.lambda. of a diameter. PA1 (4) The hydrophilic property of melamine or cyanuric acid is high, whereby it is necessary to dry it before fabrication and to take care of moisture at the fabrication.